The present invention relates to an apparatus for providing a flexible mount assembly for securing at least one thermally dynamic article subject to significant thermal expansion.
Typically, thermally dynamic materials such as polyvinyl chloride, polypropylene, polyethylene, and the like have an expansion coefficient of about six thousandths of an inch per inch/xc2x0 F. Accordingly, when mounting relatively large pieces of thermally dynamic material, that is, ones on the order of about one and one half feet long or longer, the thermal expansion of the piece can become a problem if mounted to a material having a substantially different coefficient of thermal expansion, particularly for products that are used outdoors. For these reasons, thermally dynamic materials have not been typically used to fabricate the tops of trailers or similar articles because it has been difficult to accommodate thermal expansion and provide a proper seal from moisture between the top and the less thermally dynamic conjoined sides. Instead, materials having significantly smaller coefficients of thermal expansion have been used for the fabrication of tops of trailers or similar articles. Such materials typically included fiberglass or sheet metal. While fiberglass materials tend to serve their function, they are brittle, cumbersome to cut and form due to their fibrous nature, and more expensive than is desirable. Sheet metal is typically less brittle and easier to work with than fiberglass materials; however, it is more costly than is desirable for many applications. Thus, there exists a need for a mounting system which can accommodate the thermal expansion inherent with the use of larger pieces of relatively inexpensive thermoplastics.
One attempt to provide a mounting system for fiberglass materials is described in U.S. Pat. No. 2,822,588 issued to West. The West patent is directed to a joining strip for securing the edges of adjacent fiberglass material which include channels for receiving the longitudinal edges of the sheets. Resilient members are positioned partially in undercut grooves communicating with the channel. The resilient members have flange portions which are distorted when engaged by the fiberglass sheet to provide a xe2x80x9cfriction fitxe2x80x9d between the sheets and the strip. Such xe2x80x9cfriction fitxe2x80x9d joining strips disclosed in the ""588 patent are disclosed as being for awnings, patio or window construction without additional fasteners. However, they are believed to provide a less robust securement than is required for xe2x80x9chigh stressxe2x80x9d application such as trailer tops and other environments where high strength and durability are necessary.
U.S. Pat. No. 3,363,383 issued to LaBarge is directed to a flexible joint seal between two or more substantially rigid structural members. It includes an elastomeric element adapted for sealing joints between two or more rigid panels. The panels are rigidly secured against suitable conventional supporting or framing elements such as the structural angles 44 by blind rivets 46. The sealing elements of the LeBarge patent act as a seal and closure between the rigidly mounted panels rather than a flexible mounting system for securing a thermally dynamic material.
One object of an embodiment of the present invention is to provide a flexible mounting system for the mounting or conjoining of at least one of a thermally expandable and thermally inert structure, such as the conjunction of a thermally dynamic top covering of a trailer to its corresponding side walls.
Another object of an embodiment of the present invention is to provide an air and water impermeable flexible mounting system for the mounting or conjoining of at least one of a thermally dynamic structure, having a relatively large coefficient of thermal expansion, and a thermally inert structure. Additionally, such an embodiment also allows for the flexible mounting or conjoining of two thermally dynamic structures having similar, yet great, coefficients of thermal expansion.
Still another object of an embodiment of the present invention is to provide a flexible mounting system for the mounting or conjoining of a plurality of at least one of a structure, being thermally inert, and thermally dynamic sheet, having a relatively large coefficient of thermal expansion, to another thermally dynamic sheet or thermally inert structure.
These and other objects of the invention are provided by one or more of the embodiments of the invention claimed herein. A first embodiment of the invention is directed to a mounting system for securing a thermally dynamic sheet to at least one structure, which includes an elongated track affixed to the thermally dynamic sheet or the structure. An elongated flexible mounting bracket is affixed to the thermally dynamic sheet or the structure. The elongated flexible mounting bracket has a foot portion adapted to slidably mount in the elongated track to provide sliding movement of the elongated flexible mounting bracket along a first axis of the thermally dynamic sheet or the structure. The system of the invention can accommodate thermal expansion/contraction in the first axis by sliding movement of the foot in the bracket and in the direction transverse to the first axis by flexing of the flexible mounting bracket. The terms xe2x80x9cslidably retained,xe2x80x9d xe2x80x9cslidably mountedxe2x80x9d and xe2x80x9csliding movementxe2x80x9d as used herein mean that the flexible bracket can at least xe2x80x9ccreepxe2x80x9d along the track to accommodate thermal expansion or contraction in at least one axis of the sheet, and do not require that the foot is capable of freely sliding within the track. Using this system, applicant has found that relatively large sheets of thermally dynamic thermoplastic materials have been mounted along at least one edge to a relatively thermally non-dynamic or inert structure, such as sheet metal, and that the mount can accommodate wide variations in temperature while maintaining the integrity of the mount, sheet, and structure. It is preferred that the flexible mounting bracket include a clamping portion for encompassing at least one edge of the thermally dynamic sheet or the structure.
Another embodiment of the present invention is directed to a mounting system (for thermally dynamic trailer covering including, a trailer with a side wall and end wall. A thermally dynamic covering is mounted to the trailer side wall and end wall by an elongated track affixed to the trailer side wall, the trailer end wall, or the thermally dynamic covering. An elongated flexible mounting bracket is affixed to the trailer side wall, the trailer end wall, or the thermally dynamic covering. The elongated flexible mounting bracket has a foot portion adapted to slidably mount in the elongated track. Utilizing the mounting system of the invention, applicants have determined that a variety of inexpensive, thermally dynamic materials may be used to provide a structurally strong, water-tight covering for trailers.
A still further embodiment of the invention is directed to a method of mounting a thermally dynamic sheet to a structure, including the steps of: (a) adhering an elongated flexible mounting bracket having a foot portion to the thermally dynamic sheet or the structure to form an adhered assembly; (b) placing the adhered assembly in contact with the thermally dynamic sheet or structure which lacks the adhered flexible mounting bracket; (c) positioning an elongated track along the thermally dynamic sheet or structure which lacks the adhered flexible mounting bracket such that the foot portion of the flexible elongated mounting bracket is retained within the track; and (d) mounting the elongated track to the thermally dynamic sheet or the structure which lacks the adhered flexible mounting bracket such that the foot portion is slidably mounted within the elongated track.